Chiral selectivity imprinting effect

To be able to attribute the binding of an MIP to an imprinting effect it is of utmost importance to show that specific recognition sites have been formed due to the presence of the print molecules during the polymerisation. This is usually done by comparisons with appropriate reference polymers. Polymers prepared without print molecules are not always the best choice, since the physical properties (surface area, porosity, etc.) of these polymers often differ from those of imprinted polymers. Reference polymers prepared with the optical antipode or a racemic mixture as the print species are preferred. The selectivity will be reversed when using the optical antipode and a racemic mixture will give a polymer incapable of separating the two enantiomers (unless the monomer(s) is/are chiral). 

Based on chiral functional monomers such as (15) in Table 5.6C MIPs capable of chiral resolution can be prepared using a racemic template. Thus, using racemic N-(3,5-dinitrobenzoyl)-a-methylbenzylamine (16 in Table 5.6C) as template, a polymer capable of racemic resolution of the template was obtained [86]. Another chiral monomer based on L-valine (17) was used to prepare MIPs for the separation of dipeptide diastereomers [94]. In these cases, the configurational chirality inherent in the pendant groups of the polymer are to some extent themselves chiral selectors and the effect of imprinting is merely to enhance the selectivity. Alternative approaches to imprint peptides via strong monomer-template association have recently been... 

An alternative approach to effect chiral discrimination is to use the technique of molecular imprinting, the subject of this book. This technique, sometimes also referred to as template polymerisation, results in synthetic polymers of predetermined selectivity. Receptor-like binding sites are tailor-made in situ by the copolymerisation of cross-linkers and functional monomers, which are interacting with... 

Brunkan NM, Gagne MR (2000) Effect of chiral cavities associated with molecularly imprinted platinum centers on the selectivity of hgand-exchange reactions at platinum. J Am Chem Soc 122 6217... 

---